THE HARMONY OF THE SPHERES

THE DISCOVERY OF LIFE BEYOND EARTH WOULD TRANSFORM not only our science but also our religions, our belief systems and our entire world view. For in a sense, the search for extraterrestrial life is really a search for ourselves--who we are and what our place is in the grand sweep of the cosmos.

Contrary to popular belief, speculation that we are not alone in the universe is as old as philosophy itself. The essential steps in the reasoning were based on the atomic theory of the ancient Greek philosopher Democritus. First, the laws of nature are universal. Second, there is nothing...